It is a tale of sex, debt and rock'n'roll that is unlikely to have a happy ending. When Guy Hands, a City financier with a penchant for fast food and an insatiable appetite for deal-making, came up with a plan to buy EMI, Britain's flagship music company, using billions of pounds of borrowed money, many wondered how he could possibly make a decent return on his investment. As it has turned out, he couldn't.

This weekend EMI's new chairman Charles Allen, the former ITV chief executive hired by Hands last week to run the music arm of the company, is battling to ensure its independence, assembling a rescue plan for the company that signed the Beatles and became synonymous with the golden age of British pop.

Sources close to the company say Allen, a former accountant whose eclectic musical tastes encompass Lily Allen and Edith Piaf, is "rolling up his sleeves" and working to ensure the company does not breach the terms of its bank loans, but there is no doubt EMI is in peril. "It is a very, very big moment," according to Claire Enders, founder of media consultancy Enders Analysis. "The next two or three months are critical for the future of EMI."

Allen's predecessor, Elio Leoni-Sceti, left suddenly last week just as the final touches were being put on a rescue package, prompting fears over the company's future. The business is effectively being propped up by its past, surviving on the revenues generated by artists signed during a 30-year period when British music dominated the world.

The list of talent on EMI's books reads like a roll call of rock royalty: David Bowie, Queen, Lennon and McCartney, the Sex Pistols and Pink Floyd. As an incubator of home-grown musical talent, the company is without equal and its position as one of the "big four" global record labels is a source of national pride; it exists to make money but EMI also safeguards the country's status as a place where music that matters is made.

If EMI disappears or falls into foreign hands, many music industry figures worry that future generations of British acts may find it more difficult to find a worldwide audience. Jazz Summers, who manages former Verve vocalist Richard Ashcroft, who is signed to EMI, said: "If you look at their track record, they have broken more British acts in America than anyone else, and the same is true in other countries."

EMI is in crisis because it is burdened with what sources close to the company describe as a "ludicrous" amount of debt, racked up after it was bought in 2007 by Hands's private equity company Terra Firma. EMI Music currently has three artists in the top 15 of the album chart for the first time this century, including Blur vocalist Damon Albarn's Gorillaz, and it is on course to make a profit of £200m this year, but a staggering three quarters of that will go on interest payments.

Hands borrowed heavily to fund the deal, using money provided by Terra Firma's investors, and EMI's valuable back catalogue, as collateral, but even then some questioned whether he was right to pay the amount he did for a business that was struggling to come to terms with downloads and a dramatic decline in physical music sales. The industry has lost between 30% and 50% of its revenues in the last five years, but the irony is that EMI is currently outperforming its peers, which include Sony BMG and Warner Music.

It had the biggest-selling album of 2008, Coldplay's Viva La Vida, and reissued the Beatles digitally remastered back catalogue last year. Acts including Lily Allen and Katy Perry are selling well, but the way the company is structured means it cannot trade its way out of trouble.

Before the credit crunch, loans could be refinanced cheaply, but now EMI is struggling to meet its debt repayments in the wake of the severe economic downturn. It has been forced to cut costs dramatically, laying off close to 20% of its workforce. The company is now worth £450m, around a tenth of what Hands paid for it. Some big acts, including Radiohead, have already left, muttering that the money men simply didn't understand the music business.

Last week one of EMI's biggest-selling groups, Pink Floyd, won a court action preventing the company from making tracks from their 1970s album Dark Side of the Moon available to download individually. That was widely portrayed as a victory for artistic integrity – the group want their masterpiece to be consumed from start to finish, as they originally intended – but it also illustrates the challenges the music industry faces in an era of huge upheaval, when illegal downloading is costing it dear and making money from talent discovered and developed at huge cost is more difficult than ever.

If Allen cannot persuade Terra Firma's investors to stump up another £120m, EMI will be in breach of its loan terms, and its main creditor – US bank Citigroup – could seize control of the company. If it does so, Citigroup is likely to sell it to Warner Music, an American rival which was outbid by Hands for EMI three years ago. The situation is complicated by Terra Firma's decision to sue Citigroup in New York, accusing it of forcing EMI towards administration so it can take possession of the company and make a profit from a quick sale, allegations that the bank denies.

Hands is a larger-than-life tax exile, a hero in the Square Mile whose reputation has been badly tarnished by the EMI debacle. He now concedes he overpaid for EMI, but his miscalculation means he could be about to hand a much-loved cultural institution into the keeping of the Americans.

At the end of last year Cadbury's city shareholders agreed to sell the nation's favourite chocolate company to Illinois-based Kraft. The prospect of another household name passing into foreign ownership, particularly a national champion in one of the few industries in which Britain still excels, is an unsettling one.

One senior music industry executive explained: "For British music, the fact that there was a very successful British company to sign for was hugely significant." However, others say the temptation to indulge in flag-waving should be resisted. Enders said: "Britain is one of the places people come looking for talent and that won't change. There are a lot of players in the market and advances paid to acts such as Florence and The Machine have gone up."

If EMI does fall into the hands of an American rival, she added, it might ultimately safeguard its future. "It would be better for EMI to have less indebtedness. It will have much more firepower."

EMI could survive. It is still lining up the sale of some prized assets. It was reported last month that the Abbey Road studios in London could be sold off. The company later insisted the studios should stay under its ownership and was working with "third parties" about funding a "revitalisation project".

Raising the possibility that a part of the nation's cultural heritage could be sold provides a graphic reminder of how the company's huge debt is forcing it to make unpopular decisions.

It may not matter if British acts are no longer championed by a UK company as long as the country continues to produce talent and A&R men from overseas arrive here in search of the next Lily Allen or Amy Winehouse. "In the end the music business is the same as it ever was," Enders said. "It's about hits."